The present invention relates to recording devices and pertains particularly to strip chart recorders. Condition recording devices for recording conditions in cargo containers and vehicles during shipment have been known and used for some time. Such recorders typically are arranged to record a condition versus time on a strip chart during storage or transit of cargo. This information is valuable in determining causes of damage and loss during storage or shipment.
These recorders have been devised for recording a number of different conditions, such as temperature, shock, vibrations, radiation flux density, and other conditions and factors which may affect the contents of a cargo space or container.
The reliability of the information recorded on a chart is a function of the reliability of the instrument as well as its ability to provide a tamper proof record. Many prior art recorders, while reliable in operation, fail to provide a secure chart which cannot be tampered with. As a result of this a record may be altered during or after shipment.
It is accordingly desirable that a strip chart recording instrument be available which provides security against alteration thereof, either during or after the recorded event.
It is also desirable that an instrument be available which is reliable and provides means for identification of the recorded events, time, etc.